I'm pretty sure the stock Y pipe is 2.25" - it may help with some backpressure...increasing...low end torque.
Either way, 1/4" isn't going to make that much of a difference. 3-5WHP. Butt dyno doesn't even pick that up.
Either way, 1/4" isn't going to make that much of a difference. 3-5WHP. Butt dyno doesn't even pick that up.